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A problem that has become apparent in my waaaghly endeavors against the tin can space marines is the effectiveness of their venerable CC dreads against my ork mobs.
Being furiso means the dread can have up to 7 str 10 attacks against my boyz and venerable means that I have to roll high, then high again, then high a THIRD time with powerklaws to destroy the dread. Since anything but a wrecked or explode roll will severly effect the dread, it comes down to the fact that my squad of 20 boyz is kept in the entire game dying one after the other against this foe.
Lootas are fairly useless since they will get mulched by the drop-podded dread in the first round and the orks have few other reliable anti-armour against such a foe.
Kannons manned by Gretchin could be effective. The best thing I could say though is to attack with multiple units, like say 2 units of trukk boyz. 2 power klaws are better than 1!
Also, don't throw nobz at it whatever you do. The nobz with power klaws will go last and will be instant killed unless they get their invulnerable save to work. And if your nobz are like my nobz that's the moment they're more concerned with the choppiness of their big choppa than ducking the DCCW.
"Orks have to be followers of Nurgle! They're green, smell bad, and just want to spread the fun!"
Mulched in the first round? The dreads can't assault the turn they drop pod in, so you should have a turn to counter them. Of course, they might have a flamer, or other nasty surprises, but in that case the problem might be only having one unit of lootas. I use two units of 9, a good distance away from each other.
As for dreads, units of boyz with powerklaws buried inside are the best way to go, if lootas aren't working. Rokkit buggies also work well, especially since they're fast enough to whip around and get back armor.
"Any job worth doing, is worth doing with a powerklaw."